3 42 ORGANIC LIFE. 



is thus thickly peopled with living atoms invisible to 

 the naked eye. Samples of water taken up by Schayer 

 in 57 S. lat., on his return from Van Diemen Island, as 

 well as those taken between the tropics in the middle of 

 the Atlantic, shew that the ocean water in its ordinary con- 

 dition, without any appearance of discoloration, contains 

 innumerable microscopic organisms, quite distinct from 

 the siliceous filaments of the genus Chsetoceros, floating in a 

 fragmentary state like the oscillatoria of our fresh waters. 

 Some polygastrica which have been found mixed with sand 

 and excrements of penguins in the Cockburn Islands, appear 

 to be generally distributed over the globe ; other species belong 

 to both the arctic and antarctic polar regions. ( 421 ) Thus we 

 see that animal life reigns in the perpetual night of the depths 

 of the ocean, while on continents, vegetable life, stimulated 

 by the periodical action of the solar rays, chiefly predominates, 

 The mass of vegetation on the earth very far exceeds that of 

 the animal creation ; for what, in point of bulk, would be an 

 assemblage of all the great cetacese and pachydermata living at 

 one time, compared to the thickly-crowded colossal trunks of 

 trees of 8 and 12 feet in diameter from the tropical forests 

 which cover only one region of the earth, namely, that eonv 

 prised between the Orinoco, the Amazons, and the Rio da 

 Madeira ? If the characteristic aspect of different portions of 

 the earth's surface depend conjointly on all external pheno- 

 mena, if the contours of the mountains, the physiognomy 

 of plants and animals, the azure of the sky, the form of the 

 clouds, and the transparency of the atmosphere, all combine 

 in forming that general impression which is the result of the 

 whole, yet it cannot be denied that the vegetable covering 



